With the May Day holiday approaching and the World Expo starting on May 1, Shanghai and other cities in the Yangtze River Delta are seeing an influx of tourists by rail.

The Shanghai Railway Bureau announced on April 23 that tourists traveling to the Yangtze River Delta's hot spots from around China and Shanghai will rise 8.1 percent from the same period last year, and around 3,850,000 tourists from April 30 to May 4 are expected.

Shanghai residents flocking to get out of the city for the holiday and the influx of Expo tourists are the main cause for the increase in visitors to the region, according to the railway authorities.

"I went to a booking office for tickets leaving on April 30 for Yangzhou but was told that all tickets leaving on that day were sold out," said Chang Tian, a local resident who planned to spend her holiday outside of the city Sunday.

There are only around 100 tickets left for tourists heading to Shaoxing from Shanghai on April 30, the first day of the holiday, and no more than 50 tickets are left for those going to Ningbo as of Sunday evening, according to the Shanghai Railway Bureau.

"There are no places left on our train tours to neighboring cities during the holiday," said Meng, a travel agent with china-lxlx.com, a firm specializing in travel around Shanghai.

The Shanghai Railway Bureau has decided to add 39 trains running between cities in the Yangtze River Delta area, including seven between Shanghai and Nanjing and four between Shanghai and Hangzhou.